Wunderlich syndrome (WS) is an uncommon cause of flank pain wherein spontaneous bleeding occurs into the subcapsular and perirenal spaces of the kidney. İt is most commonly attributed to renal tumors, especially angiomyolipomas. We report a case of a patient who presented to an emergency department (ED) with flank pain and symptoms of hemodynamic instability; radiologic imaging led to the diagnosis of WS. The patient’s condition was managed conservatively first; then, selective embolization was performed. For patients who present to ED with flank pain and negative hematuria, an important diagnosis that can be fatal, if not recognized early, is WS. İt is classically presented with acute flank pain, flank mass, and hypovolemic shock, together known as Lenk’s triad. İt can be fatal if not recognized and managed early, and radiological confirmation is required for accurate diagnosis.Therefore, physicians in ED should keep this syndrome in mind to prevent misdiagnosis (for e.g., as renal colic pain); and thereby the mortality.